Configuration page comments

[Quetzacoalt91]

• Module description is missing on the configuration page. Better, but can be still improved (with a logo in example)
• When the pl language is not installed, the configuration page is quite useless.
  • The warning should be an error
  • The navigation bar should not be shown
  • A link to the languages setting should be added.
• When the module is not configured yet, the Settings button in the bar should be selected by default an the other ones should not be clickable. For example, you can change the mouse pointer for a forbidden icon when it hovers the disabled buttons.

I also tried to configure the module to make it work, without success.

• DPD poland are never shown on the carrier list.
• I get the following error (not explicit) when I try to arrange a pickup:
  

[Quetzacoalt91]

Updated